Megakaryocytes in the acute stage of experimental hemorrhagic shock. Part II. Megakaryocytic regulation of cell release from the bone marrow.

The contribution of MK to the release of other marrow cells to the blood was evaluated in rats subjected to experimental hemorrhagic shock. The analysis was based on the frequency of emperipolesis phenomenon in megakaryocytes, which was evaluated in a light microscope on marrow smears and in ultrastructural examinations. A considerable increase was found in the number of marrow cells in the MK cytoplasm in the animals examined, which indicates a significant part of MK in the release of these cells to the blood and in the marrow-blood barrier formation by MK.